Entasisograph.



N0. 692,|47. Patented Ian. 28, I902.

G. KIMBRELL.

ENTASISOGRAPH.

. (Application filed Aug. 28, 1901.)

(No Model.) 2 Sheets-Sheet I.

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UNITED STATES PATENT OFFICE.

GEARY KIMBRELL'OF PENDLETON, OREGON.

ENTASISVOGRAPH.

SPECIFICATION forming part of Letters Patent No. 692,147, dated January28, 1902.

Application filed August 28, 1901. Serial No. 73,600. (No model.)

To aZZ whom it may cOnccrn:

Be it known that I, GEARY KIMBRELL, a citizen of the United States, anda resident of Pendleton, in the county of Umatilla and State of Oregon,have invented a new and Improved Entasisograph, of which the followingis a full, clear, and exact description.

The object of this invention is to provide a novel instrument especiallyadapted for accurately and quickly drawing the entasis of a classiccolumn, which may be either of the Ionic, Corinthian or composite order,and an instrument that by its employment will onable any draftsman toexecute a more perfect drawing than an expert can with the usual meansemployed and also effect a considerable saving of time.

The invention consists in the novel construction and combination ofparts, as is hereinafter described, and defined in the appended claims.

Reference is to be had to the accompanying drawings, forming a part ofthis specification, in which similar characters of reference indicatecorresponding parts in all the figures.

Figure 1 is a partly-sectional side view of theimproveddrawinginstrument. Fig.2is anenlarged plan view of one end ofthe same, which embodies the main features of the invention. Fig. 3 is aplan view of portions of the device represented in Fig. 2, but arrangeddifferently, part being shown by dotted lines. Fig.

- 4 is an enlarged detached side view of a drawing-pen of novelconstruction. Fig. 5 is a view similar to Fig. 4, showing the noveldetail in section. Fig. 6 is an enlarged detached side view of a novelslide-block employed; and Fig. 7 is a plan view of the improvement asapplied, the delineation of the entasis of half of a column beingindicated by dotted lines.

The type of classic column the improved instrument is employed indrafting has a slightly-curved outline which in all cases extends theentire height of the columnfrom its base to the top, and as this slightswell of the column is not the arc of a true circle, but changesgradually in degree of curvature, it is ordinarily a difficult andtedious undertaking to accurately draw the entasis of such a column withthe exactitude that is essen' tial for the correct proportion and ornateappearance of the same.

In Fig. 7 one-half of a column is shown by dotted lines, and the usualway employed in projecting the entasis or variable swell thereon is alsoindicated by dotted lines. In the same figure is shown the method ofusing the improvement, which plainly illustrates the advantages affordedby the novel instrument which will be hereinafter described.

Ordinarily the draftsman,on drawing-paper mounted upon the board A,projects a line w 00 parallel with the side edge A of the board A. Aline 00' is projected upwardly from the base of the column andterminates at the top of the column, this line representing the exteriorcontour of the column, which in this style of plain or fluted columnsgradually increases in diameter from the base of the colu mn toward thecenter and then diminishes in thickness toward the cap-piece of thecolumn. From a suitable point I), that is taken on the line w, aplurality of radial lines '1 are drawn toward line 00'. The usual methodof forming the variable swell defined by the line m is as follows: AT-square B is so placed uponthe board A that its edge nearest the line09' is removed therefrom a distance equal to onehalf of the diameter ofthe column, and therefore indicates the perpendicular axis of the same.The draftsman,withspacing-dividers, takes the distance between this edgeof the T-square and the point 00 and then lays 0H": this distanceon eachradial line y from the axis of the column as defined by the edge of theT-square, these points when joined by an arched line drawn through themdefining the entasis of the column. As it is difficult to draw acontinuous line of variable curvature by successive use ofdifierent-curved guides, the draftsman must be very expert to execute atrue and properly-defined entasis by the means just described.

The instrument which I have devised affords means to draw a true entasisof any desired proportion without radial lines being necessary, as willappear from the following description.

In the drawings, 10- indicates a beam of suitable length, that ispreferably of plate metal and may with advantage be gradually taperededgewise from one end or head of the beam toward the opposite end of thesame. A slot at is formed at the transverse center of the beam andextends from a point near the head of the beam to another near theopposite end, as clearly shown in Fig. 7.

In the slot at the cylindrical upper end I) of a fulcrum-post is looselyintroduced, the beam being seated upon a shoulder b, that is at the baseof the post, and preferably the body of the fulcrum-post is increased inarea so as to provide a base-flange b at a suitable distance from theshoulder b. Centrally from the base-flange b a pointed anchor-pin 5projects, which in service is forced into the board A at a point thatdefines the common center of the variable curve to be drawn by theinstrument.

At the head of the beam 10 two similar fingers c are formed thereon,having equal thickness with said beam. The fingers a curve toward eachother, and, as shown in Figs. 2 and 3, their inner edges merge into eachother and define a true are of a circle, which preferably exceeds asemicircle.

The drawing-pen 1.1 (shown clearly in Figs.

4 and 5) comprises a leg d, that is a fixed projection from the handle dof the instrument and curves down to the point or nib (P.

In a perforation in the hinged leg 6 the body g of an adjusting-screw isloosely inserted,

the head g thereof being of considerable dimensions and preferablymilled on its periphe ery to adapt it for convenient manipulation.

The screw 9 engages a tapped perforation in the fixed leg (1, thusadapting it when turned in the right direction to draw the point (2toward the point 01 to form a point for the pen, overcoming the stressof the spring-leg e when the latter is arrested by contact with thedepending lower portion d of the handle. d.

Upon the. leg 01 a coupling-piece 12 is formed or affixed, that consistsof a circular block having a central peripheral groove h formed therein.The groove h is fiat on the bottom and parallel on the sides, havingsuch pro.-. portionate width as permits two. substantial flanges h h -toproject in parallel planes from the opposite. edges of the block. Thespace between the flanges h h is slightly in excess of the thickness ofthe fingers 0, so thatsaid fingers may be slidably introduced within thegroove h if the coupling-piece and end of the beam 10 are disposedoppositely in the relative positions indicated by full and dotted linesin Fig. 3.

To permit the. leg 8 to play in the. block 12, a slot or opening 2' isformed in said block, which extends outwardly from the. inner side ofthe. leg (1, so that the leg 6 may occupythe slot and receive.adjustment as occasion may require.

Preferably the upper flange h of the coupling-piece 12 is reduced inextent and so shaped as. to. approach a crescent form,while.the lowerflange. k is extended around the lower edge of the block 12, and it willbe seen that when in position the drawing-pen may be rotated upon theend of the beam 10 and have its nibs d 6 when they are closely adjusteddisposed centrally within the arc of the circle that defines the inneredges of the fingers c.

A slide-block 13 is provided as a completing member of the novelinstrument, which is preferably termed an entasisograph. As shown, theslide-block 13 is parallel on the top and bottom faces and of suitablewidth to insure a proper bearing therefor upon the lower surface of thebeam 10. A rib-like flange 1 projects centrally from the upper surfaceof the slide-block 13 and longitudinally thereof, the rib having asliding fit within the slot a of the beam 10. A threaded stud 14projects Vertically from the rib n intermediately of its ends, and uponthe stud a clamping-nut 15 is screwed, said nut affording means tosecure the slide-block 13 at any desired point on the beam 10.

The block 13 is preferably rounded on the end which in service isnearest to the drawing-pen, and this end portion is reduced in thicknessby the removal of material from its upper side, said reductionpermitting the forward end of the slide-block to pass below the lowerflange 72/ Upon the front edge of the block 13, at the transverse centerof the thinner portion 0, a guide-toe 0 is formed or secured, whichprojects downward at a right angleto the lower surface of theslide-block, and it will be seen that the too 0 may be disposed in closeproximity to the pointed end of the drawing-pen by a forward adjustmentof the block 13.

In arranging the instrument for service the drawing-pen is loaded withink and the beam 10 engaged with the pin 1) on the fulcrumpost, whichhas previously been bedded in the drafting-board A at a proper distancefrom the forward edge of the T-square blade B, held transversely of theboard A, as shown in Fig. 7.

The upright dotted line so may represent the. side of a column which iscompleted by defining the entasis thereof that extends up wardlyf-romthe base x and represents the entire height of the column. Theslide-block 13 is now adjusted so that the guide-toe 0' will engage theforward edge of the T-square blade B when the point of the loadeddrawing-pen is positioned directly over the point x atthe base of thecolumn to be drawn. The draftsman now slides the beam -10 toward the topend of the column to be drawn, said beam being rested upon the T'-squareblade B. The operator holds the too 0' in close. engagement with theforward edge of the T-square blade while moving the beam and at the sametime holds thedrawingepen steady, so thatits point will draw an ink-lineon the. drawing-paper. Now, as the distance between the toe. o and thepoint of the pen remains constantly the same, it will be seen that thetraverse of the toe along the blade B will draw the beam 10 forwardlyand exactly define a true entasis for seam? one side of a column, whichmay be completed While it is preferred to employ a pen and ink indelineating the entasis of a column, it is obvious that a drawing-pencilor a steel point may be placed in the drawing-pen and be substituted forthe pen that marks with ink.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- 1. A drawing instrument for delineating variablecurves, comprising a beam having a longitudinal slot, a fulcrum-postloosely engaging the slot, a slide-block having a depending toe passingdown through the slot, means for securing the slide-block on the beam,and a pen or the like loosely held upon one end of the beam.

2. A drawing instrument for delineating variable curves, comprising abeam havinga longitudinal slot, a fulcrum-post loosely engaging theslot, a slide-block, a depending toe on one end of the slide-block, arib on the slide-block engaging the slot in the beam, means for securingthe block at any point along the slot in the beam, and a pen or the likeloosely held upon one end of the beam.

3. A drawing instrument for delineating variable curves, comprising abeam having a longitudinal slot, curved fingers at one end of the beam,9. drawing-pen or like device having a flanged circular coupling-blockon one leg, and adapted to loosely receive the curved fingers, aslide-block, a depending toe on one end of the slide-block, a rib onsaid block loosely engaging the slot in the beam, means to secure theblock in said slot, and a fulcrumpost securable in a drawing-board andloosely engaging the slot in the beam.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

GEARY KIMBRELL.

Witnesses:

T. F. HOWARD, J. R. RALEY.

